April 2014 

NASA/CR–2014-218249 

Calibration of International Space Station (ISS) 

Node 1 Vibro-Acoustic Model—Report 2 

Weiguo Zhang and Ravi Raveendra 

Comet Technology Corporation, Ann Arbor, Michigan 
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Hampton, Virginia 23681-2199 under Contract NNL07AA00C 

 

April 2014 

NASA/CR–2014-218249 

Calibration of International Space Station (ISS) 

Node 1 Vibro-Acoustic Model—Report 2 

Weiguo Zhang and Ravi Raveendra 

Comet Technology Corporation, Ann Arbor, Michigan 
Available from: 

NASA Center for AeroSpace Information 

7115 Standard Drive 

Hanover, MD 21076-1320 

443-757-5802 
- 

 1 

1. Introduction 

The objective of the present investigation is to correlate the vibration data measured by NASA 

using acoustic emission, at specific sensor locations on Node 1 of the International Space Station 

(ISS), to corresponding values predicted by Comet EnFlow, an analysis software for high 

frequency vibro-acoustic analysis based on Energy Finite Element Method (EFEM) that was 

developed previously as a result of an SBIR funding from NASA LaRC. Previously, analysis 

performed based on a source located at sensor location 13 was reported. In this report, responses 

due to sources located at additional locations are evaluated and compared to measurements. The 

source and sensor locations used in the present study are shown in Figure 1. The measured data 

sets due to sources at locations 10, 2, 11, 8 and 5 are provided by NASA. Sources 10 and 2 are 

located at the barrel section of the model. Source 11 is located at port hatch. Sources 8 and 5 are 

located at forward cone and aft cone, respectively. 

Sensors that were used in the previously reported study are also used presently and the measured 

data are processed similarly. However, unlike source 13 which was generated by an actual leak, 

the sources investigated in this study were driven by a piezoelectric sensor to simulate the leak. 

Further, the sensors were not placed very close to the source location and as a result it is not 

feasibly to obtain input power accurately as before. The approximate total input power generated 

through the excitation at the source locations are computed based on the response of the closet 

sensor. Additionally, the sources are decomposed into direct and reverberant fields with 

associated regions (areas) as was done in the second part of the previously reported analysis. 

Also, the damping coefficients identified in previous work are utilized in the present study. 

Figure 1.1 Source and Sensor Locations on Node 1 Wall 
2 

2. Results 

The calibration results corresponding to sources 10, 2, 11, 8 and 5 are sequentially presented. 

2.1 Source 10

The locations of source 10 and sensor 6 are shown in Figure 2.1.1. The direct field region is 

taken to be the pink area around source 10 (note that the sensor location is outside the direct field 

region. The reverberant filed generated at the boundary of the pink patch is transmitted to the 

other parts of the model. The approximate total input power generated through the excitation at 

source 10 location is computed based on the response of the sensor 6. The flexural velocities 

computed at all sensor locations using Comet EnFlow are compared to measured velocities in 

Figures 2.1.2 - 2.1.8. These figures are arranged according to the distance from the sensors to the 

location of excitation (from near to far). 

Figure 2.1.1 Source 10 location
 3 

Figure 2.1.2 Flexural Velocity of Sensor 6 

Figure 2.1.3 Flexural Velocity of Sensor 1 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 4 

Figure 2.1.4 Flexural Velocity of Sensor 2 

Figure 2.1.5 Flexural Velocity of Sensor 4 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 5 

Figure 2.1.6 Flexural Velocity of Sensor 5 

Figure 2.1.7 Flexural Velocity of Sensor 7 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
6 

Figure 2.1.8 Flexural Velocity of Sensor 3 

2.2 Source 2

The locations of source 2 and sensor 2 are shown in Figure 2.2.1. The approximate total input 

power generated through the excitation at source 2 location is computed based on the response of 

the sensor 2. The direct field is included in the pink area surrounding source 2. The reverberant 

filed is generated at the edge of the pink area. As in the previous case, the sensor is located 

outside the direct field region. The flexural velocities at all sensor locations are compared as 

before in Figures 2.2.2 - 2.2.8. 

Figure 2.2.1 Source 2 location 

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 7 

Figure 2.2.2 Flexural Velocity of Sensor 2 

Figure 2.2.3 Flexural Velocity of Sensor 1 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 8 

Figure 2.2.4 Flexural Velocity of Sensor 4 

Figure 2.2.5 Flexural Velocity of Sensor 6 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 9 

Figure 2.2.6 Flexural Velocity of Sensor 5 

Figure 2.2.7 Flexural Velocity of Sensor 7 

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 10 

Figure 2.2.8 Flexural Velocity of Sensor 3 

2.3 Source 11

As indicated in the previous report, responses (flexural velocities) can be predicted using (a) total 

field, or (b) decomposed fields (i.e. by separating the total field into direct and reverberant fields). 

Previous analysis, presented in the first report, has indicated that the decomposition of the total 

field into direct and reverberant fields improves the accuracy of the predicted responses. When 

decomposing the total field, typically, the direct field region is assumed to be a small patch of 

area around the source. In order to estimate the source and subsequently the responses accurately, 

the sensor location must be within the direct field region (preferably very close to the source 

location). However, in the present study, the source and sensor locations are not close to each 

other and as a result the sensors could not be located within the direct field region. In these 

situations, it is expected that the responses predicted using total and decomposed field will be 

similar (this is confirmed by the investigation reported in the Appendix of this report). As a 

consequence, analyses are performed using total fields without decomposition in the current and 

the ensuing cases. 

The locations of source 11 and sensor 1 are shown in Figure 2.3.1. The approximate total input 

power generated through the excitation at source 11 location is computed based on the response 

of the sensor 1. As shown in Appendix A, the velocities predicted using total field without 

decomposition and decomposition of the total field into direct and reverberant fields does not 

make noticeable difference. Thus, the flexural velocities at all sensor locations are computed 

using total field and these are compared to measurements in Figures 2.3.2 - 2.3.8. 

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 11 

Figure 2.3.1 Source 11 location 

Figure 2.3.2 Flexural Velocity of Sensor 1 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 12 

Figure 2.3.3 Flexural Velocity of Sensor 6 

Figure 2.3.4 Flexural Velocity of Sensor 2 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 13 

Figure 2.3.5 Flexural Velocity of Sensor 4 

Figure 2.3.6 Flexural Velocity of Sensor 5 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 14 

Figure 2.3.7 Flexural Velocity of Sensor 7 

Figure 2.3.8 Flexural Velocity of Sensor 3 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 15 

2.4 Source 8

The locations of source 8 and sensor 7 are shown in Figure 2.4.1. The approximate total input 

power generated through the excitation at source 8 location is computed based on the response of 

the sensor 7. The flexural velocities at all sensor locations are compared in Figures 2.4.2 - 2.4.8. 

Figure 2.4.1 Source 8 location 

Figure 2.4.2 Flexural Velocity of Sensor 7 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 16 

Figure 2.4.3 Flexural Velocity of Sensor 1 

Figure 2.4.4 Flexural Velocity of Sensor 6 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 17 

Figure 2.4.5 Flexural Velocity of Sensor 5 

Figure 2.4.6 Flexural Velocity of Sensor 2 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 18 

Figure 2.4.7 Flexural Velocity of Sensor 4 

Figure 2.4.8 Flexural Velocity of Sensor 3 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.000000001

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 19 

2.5 Source 5

The locations of source 5 and sensor 3 are shown in Figure 2.5.1. The approximate total input 

power generated through the excitation at source 5 location is computed based on the response of 

the sensor 3. The flexural velocities at all sensor locations are compared in Figures 2.5.2 - 2.5.8. 

Figure 2.5.1 Source 5 location 

Figure 2.5.2 Flexural Velocity of Sensor 3 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 20 

Figure 2.5.3 Flexural Velocity of Sensor 2 

Figure 2.5.4 Flexural Velocity of Sensor 4 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 21 

Figure 2.5.5 Flexural Velocity of Sensor 1 

Figure 2.5.6Flexural Velocity of Sensor 6 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 22 

Figure 2.5.7 Flexural Velocity of Sensor 5 

Figure 2.5.8 Flexural Velocity of Sensor 7 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 23 

3. Discussion

Overall, good correlations are observed at sensors on the barrel section for all sources. The 

correlations are better when location of sensor is close to the source location. In the present 

study, the source locations are not in the neighborhood of the sensor location. Additionally, in 

some case, junctions also exist between the sources and the sensor and therefore input power is 

further approximated due to the incorporation of the effect of energy transfer at the junction. 

Nevertheless, good correlations in most cases indicate that the input power is estimated properly. 

However, the correlations between measured and predicted results at sensors 7 and 3 are not as 

good. These two sensors are located at the two end cones, which have relatively complex 

configurations. In some cases, it is observed that the measured responses at these two sensors are 

higher than the responses at locations, which are closer to the source. The higher response 

indicates the injection of additional power at the termination of the end cone. The modeling of 

this effect may require the modification of the (end) boundary conditions in the EnFlow model to 

include the additional power. Furthermore, the support frame is connected with the Node 1 

model through four pins at two end cones (see Figure 3.1). Although the frame is very stiff, it is 

possible some energy is transferred between the end cones through the frame. Some additional 

feature development in EnFlow is necessary to incorporate this energy transfer mechanism by 

special joints without modeling the frame explicitly.

Figure 3.1 Support structure of Node 1 
 24 

Appendix 

A.1 The direct field effect 

When the sensors used to estimate the input power are outside the direct field regions as in the 

present investigation, the decomposition of the total field into direct and reverberant fields does 

not have much effect on the responses. This is illustrated by studying the responses due to source 

10 studied in Section 2.1. The approximate input power at the location of excitation with and 

without direct field is compared in Figure A.1. Both computations are based on the measured 

response at sensor 6, which is outside the direct field region. 

Figure A.1 Input power comparison at source 10 

It can be seen that the input power from incorporating direct field is higher than the power 

neglecting the direct field. This is expected since some portion of total input power is dissipated 

as direct waves within the direct field region. The response at sensor 6 is generated only by the 

reverberant portion of the total input power. When the direct field is neglected, the total input 

power contributes to the response of sensor 6. The responses, computed at all sensors using input 

powers with and without direct field, are compared in Figures A.2 - A.8. As expected, these 

responses are almost identical (note that similar results are obtained for all other cases). Thus, it 

can be concluded that when a sensor, located outside the direct field region, is used to derive the 

approximate input power, the effect of direct field is not important. In order to evaluate accurate 

input power more accurately by incorporating the direct field, the sensor should be placed close 

to the source location (i.e. the source and sensor should be located within the direct field region) 

as demonstrated in the next section. 

Comparison of Input power at source 10 

0.00001

0.0001

0.001

0.01

40 60 80 100 120 140 160

Frequency (kHz)

Input Power

w/ direct field

w/o direct field
 25 

Figure A.2 Comparison at sensor 6 

Figure A.3 Comparison at sensor 1 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field
 26 

Figure A.4 Comparison at sensor 2 

Figure A.5 Comparison at sensor 4 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field
 27 

Figure A.6 Comparison at sensor 5 

Figure A.7 Comparison at sensor 7 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field
 28 

Figure A.8 Comparison at sensor 3 

A.2 Effect of Input Power Computation 

Finally, in order to illustrate the effect of the direct field, a synthesized example involving source 

and sensor locations that are next to each other is studied (note that this is similar to the actual 

case that was studied in the previous report). Again, source 10 case is considered. The correlated 

input power is obtained by trial and error since no measured response close to source 10 is 

available. A comparison of this estimated power to the measured power is shown in Figure A.9. 

Using this estimated input power, responses at all sensors are computed and these are compared 

to measured velocities in Figures A.10 - 16. As expected, better correlations are obtained at all 

sensors compared to the previously presented results in this report. Although the input power is 

generated by trial and error, it indicates that if more accurate input power is used (by placing the 

sensor close to source location), improved correlation between EnFlow predictions and 

measurements. 

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

w/ direct field

w/o direct field
 29 

Figure A.9 Input power comparison at source 10 

Figure A.10 Comparison at sensor 6 

0.00001

0.0001

0.001

0.01

40 60 80 100 120 140 160

Frequency (kHz)

Input Power

Original

Correlated

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 30 

Figure A.11 Comparison at sensor 1 

Figure A.12 Comparison at sensor 2 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 31 

Figure A.13 Comparison at sensor 4 

Figure A.14 Comparison at sensor 5 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
 32 

Figure A.15 Comparison at sensor 7 

Figure A.16 Comparison at sensor 3 

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow

0.00000001

0.0000001

0.000001

0.00001

0.0001

0.001

0.01

0.1

1

40 70 100 130 160

Frequency (kHz)

Velocity (in/sec)

Measured

Measured(Averaged)

EnFlow
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Contractor Report

 4. TITLE AND SUBTITLE

Calibration of International Space Station (ISS) Node 1 Vibro-Acoustic 

Model - Report 2

5a. CONTRACT NUMBER

NNL07AA00C

 6. AUTHOR(S)

Zhang, Weiguo; Raveendra, Ravi

 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES)

NASA Langley Research Center 

Hampton, Virginia 23681 

 

 9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES)

National Aeronautics and Space Administration

Washington, DC 20546-0001

 8. PERFORMING ORGANIZATION

 REPORT NUMBER

10. SPONSOR/MONITOR'S ACRONYM(S)

NASA

13. SUPPLEMENTARY NOTES

This work was performed by Comet Technology Corporation for Science Systems and Applications, Inc., under NASA 

contract NNL07AA00C. 

Langley Technical Monitor: Eric I. Madaras

12. DISTRIBUTION/AVAILABILITY STATEMENT

Unclassified - Unlimited

Subject Category 16

Availability: NASA CASI (443) 757-5802

19a. NAME OF RESPONSIBLE PERSON

STI Help Desk (email: help@sti.nasa.gov)

14. ABSTRACT

Reported here is the capability of the Energy Finite Element Method (E-FEM) to predict the vibro-acoustic sound fields within 

the International Space Station (ISS) Node 1 and to compare the results with simulated leak sounds. A series of electronically 

generated structural ultrasonic noise sources were created in the pressure wall to emulate leak signals at different locations of 

the Node 1 STA module during its period of storage at Stennis Space Center (SSC). The exact sound source profiles created 

within the pressure wall at the source were unknown, but were estimated from the closest sensor measurement. The E-FEM 

method represents a reverberant sound field calculation, and of importance to this application is the requirement to correctly 

handle the direct field effect of the sound generation. It was also important to be able to compute the sound energy fields in the 

ultrasonic frequency range. This report demonstrates the capability of this technology as applied to this type of application. 

15. SUBJECT TERMS

Acoustics; Finite element method; International Space Station

18. NUMBER

 OF 

 PAGES

37

19b. TELEPHONE NUMBER (Include area code)

(443) 757-5802

a. REPORT

U

c. THIS PAGE

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b. ABSTRACT

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17. LIMITATION OF 

 ABSTRACT

UU

Prescribed by ANSI Std. Z39.18

Standard Form 298 (Rev. 8-98)

3. DATES COVERED (From - To)

5b. GRANT NUMBER

5c. PROGRAM ELEMENT NUMBER

5d. PROJECT NUMBER

5e. TASK NUMBER

3-034CY2-3

5f. WORK UNIT NUMBER

401769.06.03.04.02.12

11. SPONSOR/MONITOR'S REPORT

 NUMBER(S)

NASA/CR-2014-218249

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PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS.

1. REPORT DATE (DD-MM-YYYY)

01- 04 - 2014